Feels like the passing of an era. When I got involved with rangefinders back in '97 Tom was already an established figure within the community. He continued to be so even as my own interests drifted. For me, I can't even think of Tri-X or an M2 without also thinking of Tom A. I always paid extra heed to his comments on gear, because they were almost always based on actual experience, not just something he read or heard. I never met the man, but he was always so polite on these forums, even when he didn't agree. I can only imagine what he was like in person.
Not only the rangefinder community, but photography in general has lost a valuable resource and real decent person.